With structure features of long-range disorder and short-range order which provide properties of both glasses and metals, bulk amorphous alloys have excellent physical, chemical and mechanical properties, such as high strength, high hardness, high wear resistance, high corrosion resistance, high resistance, etc., which have been applied in a wide range of fields such as national defense equipments, precision machines, biomedical materials, electric information elements, chemical industries and so on. However, because bulk amorphous alloys have a plastic depth limited at a shear band with a width of from 5 nm to 20 nm, further deformation of the bulk amorphous alloys may soften the shear band, and finally result in fracture at the softened shear surface. Non-uniform deformation of this kind may cause catastrophic failure of the bulk amorphous alloys without significant macroscopic plastic deformation, which limits superior performances and wide applications in practical use of the bulk amorphous alloys.
In recent years, a variety of bulk amorphous alloy composite materials comprising an amorphous matrix phase and a crystalline reinforcing phase have been developed by introducing a second crystalline phase into an alloy melt or by precipitating a part of crystalline phase during crystallization, for improving the plastic performance by protecting a single shear band from running through a whole specimen and facilitating the formation of a plurality of shear bands.
For example, U.S. Pat. No. 6,709,536 discloses a composite amorphous metal object and a method of preparing the same. The composite amorphous metal object comprises an amorphous metal alloy forming a substantially continuous matrix and a second phase embedded in the matrix. And the second phase comprises ductile metal particles of a dendritic structure. The method of preparing the same comprises the steps of: heating an alloy above the melting point of the alloy; cooling the alloy between the liquidus and solidus of the alloy for sufficient time to form a ductile crystalline phase distributed in a liquid phase; and cooling the alloy to a temperature below the glass transition temperature of the liquid phase rapidly for forming an amorphous metal matrix around the crystalline phase. While U.S. Pat. No. 6,709,536 improves the plastic performance of the composite amorphous metal object by introducing a crystalline phase into the composite amorphous metal, the plastic performance thereof is still poor.